Sound reproducer



M. SFRANKIN. souwn REPRODUCERJ APPLICATION FILED MAYIZ, 1921.

1,430,1 5, I Patented-Sept. 26,1922.

INVENTORQ ATTORNEY.

Patented Sept. 26, 1922.

brim s ster} nsane PATENT oar-ice.

Mortars s. RANKI or movmsm m, N'EWJERSEY.

seem) rel-sweetness.

Application filed May 12,

ferred form can be manufactured at a low' cost, and is particularlyadapted for use as a part'of toy devices of this character.

Another object is to provide an improved mounting for the stylus bar,whereby, the

same is separated Tfrom thesound box casing by a non-conducting or soundinsulating member, thus preventing the objection able scratch of theneedle in the groove of the record from being conveyed to thesaidcasing, as by a continuous metallic path.

A further object is to {provide insuch a device ar diaphragm-retaininggasket having an axially directed extension operative to form theyielding, resilient, sound-insulatingsupport for the stylus bar.

And still another object of the invention is to provide an improvedmethod of mount ing the diaphragm within the "sound box casing; toprovide an improved means for holding the stylus in co-operation withthe stylus bar of the reproducer; to provide an improved method ofattaching one end of the said stylus bar to the diaphragm; to provide animproved manner of supporting said reproducer, and other details ofconstruction and operation fully brought out in the followingdescription, when read in conjunction with the accompanying drawings inwhich Fig. 1 is a side elevation of the reproducer and the adjacent endportion of an amplifier; Fig. 2 is an enlarged diametrical section ofthe sound reproducer in its preferred form; Fig. 3 is a transversesection of the same; Fig. a is a plan view of the diaphragm free of thereproducer; and Fig. 5 is an enlarged detail perspective view of thefolded metal blank from which the stylus bar is formed.

Referring to the drawing, it will be noted that the invention relates tothe sound-reproducers for talking-machines, no other part of the samebeing illustrated except the small end of a tapering amplifier 1 and aS. RANKIN, a

- positioned a substantially cylindrical 1921. Serial No. 468,889.

line which represents the "plane "of any well-known form of'disc record.

The reproducer per se comprises an annular metallic mem er?) preferablyhaving a plane face 4, while its rear portion is provlded with alate-rally. extending. integral .projection5 having an aperture 6 whichforms the exit end of acha nnel tapering. towards the inlet 27, whichsame is prefer ably positioned centrally of the plane face of saidmember, and itis into the enlarged channel end '6 thatthe reduced endportion 8 of: the amplifier 1 is firmly positioned.

An annular. disc 'iias'l-ret 9 is provided, the same being positioned inuniform. contact with the outer marginal edge portion of the face 4 ofthe member 3, and against which gasket is positioned the peripheralportion of a. vibratory diaphragm '10, which diaphragm and gasket areboth prevented from movement with respect towthe'membe r 3 by I means ofa 'substantlally cylindrical sheet metallic member :11, having aradially inwardly direct-ed portion 12 closely surrounding the rearsurface of the said member,- while "its oppositely positioned; nmrgi'naledge portion 13 is flaredinwardly and forms a partial inclosure, withinwhich there is lket 141,. bearing at its inner edge "dire; tly againstthe outer surface of the said diaphragm ad jacent to the "periphery ofthe latter, while the union between said gaskets and diaphragm may becompletely air-tight by means of a thin layer 15 of suitable cement,which as shown in Fig. 4 preferably covers the exposed surfaces ofthegasket 14 and encroaches well upon the radially outer por. tion .of theexposed surface of said diaphragm. I

' The'said gasket 14 is provided at one point with an extension 16,against the outer surface of which is closely positioned thecorrespondingly curved arms 17 of a stylusbar 18, while the oppositelypositioned extremities 19 of said arms surround and firmly grip theopposite limiting edges of the gasket projection l6,'so that saidprojection forms a support for the stylus-bar, and also due to thematerial of which said support is formed it serves as a sound-in- Saidstylus-bar comprises a shank portion formed of two thicknesses of metalfolded together, the same being provided at their common adjacent endportions with lateral extensions 20, which are reversely bent andproject transversely beyond the shank of said bar to form spaced fingers21, which as clearly shown in Fig. 2 are adapted to extend throughspacedapertures 22 in the said diaphragm, after which said fingers arefolded to firmly grip the central apertured portion of the diaphragm inorder to insure the latter vibrating in perfect har mony with the saidstylus-bar. v

The stylus-bar supporting arm 17 when being formed actually comprisesbifurcated extensions of the folded side portions of the shank 18, whileeach. of said arms has punched. radially from its central portion an ear23, the same being provided with aligned apertures 24 and beingnormally/in parallel relationship. As shown in the drawing, a pin 25extends through the said apertures 24 and pivotally supports a cammember 26 provided with a small thumb operated lever 27, so constructedand particularly shown in Fig. 3 that a stylusneedle 28 may be insertedbetween the ears 23 of the stylus-bar and clamped in position by a.partial rotation of the said lever, from which said needle may bereadily removed as become worn by merely shifting the said lever in theopposite direction, after which as previously described a. new needle 1may be inserted in place of the former.

As the reproducer herein described is particularly adapted for use uponinexpensive and toy sound-reproducing machines, the member 3 may wellcomprise a metal casting, while the cylindrical member 12 may equallywell be formed of a drawn tin punching, the diaphragm formed of thinsheet metal, water-proofed paper product, bakelite, or the like, and thegaskets 9 and 14 of paper or the equivalent which has preferably beenpreviously Water-proofed.

Havin thus described my invention, what I cdaim and desire to protect byLetters Patent of the United States is:

1. A sound-reproducer, comprising a stylus-barformed of sheet-metalfolded to.

provide a shank portion comprising a double thickness, the sides'of saidshank portion adjacent at one end being provided with oppositelyextending fingers adapted to be secured to a vibratory diaphragm, whilethe opposite. end portions of said shank thicknesses are extendedlaterally in opposite direct-ions to provide a support for saidstylus-bar, and said arms being provided with. integral parallelextending ears adapted tocreceive between them a removable stylus, andmeans pivotally carried by and between said ears operative to removablyretain said stylus in position.

2. A sound-reproducer, comprising a diaphragm, an annular supportinggasket therefor, and a stylus connected to said diaphragm and supporteddirectly by said.

gasket.

3; 'A' sound-reproducer, comprising a diaphragm, a supporting gaskettherefor signature.

MORRIS S. RANKIN.

